可发酵碳水化合物减少猪场臭气的机理和应用

可发酵碳水化合物,添加在猪日粮中到达后肠作为微生物发酵的底物,通过改变猪肠道和粪便中的微生物及其发酵过程,改变粪尿的理化特性,来减少氨的挥发以及臭气的产生.本文对臭气和除臭方法进行了简单的介绍,并综述了通过在猪日粮中添加可发酵碳水化合物来控制猪场臭气的机理和应用效果.     

Effects of fruit bagging on coloring and related physiology,and qualities of red Chinese sand pears during fruit maturation

Red Chinese sand pears (Pyrus pyrifolia Nakai) are particular to China. In order to determine the effects of fruit bagging treatments (including bag types, bag removal patterns and dates) on fruit qualities and to understand the mechanism of coloring of red Chinese sand pears, two experiments were carried out. In the first experiment, fruit of ‘Meirensu’ were firstly covered by light-impermeable paper bags with different levels of light permeable liners during their early development stage, then, the whole bag were/not removed or only the outer layer of bags were removed 3, 2 or 1 weeks before harvest. Thus, the fruit were/not totally re-exposed or were under different levels of sunlight transmission (80.31% or 34.71%). Non-bagged fruit were used as the control. Bagging treatments significantly affected the concentration of anthocyanin and the visual qualities of pear fruit. Compared to control, fruit re-exposed totally for 2 or 3 weeks accumulated the largest amount of anthocyanin and fruit receiving 80.31% and 34.71% of sunlight for 1–3 weeks could synthesize a little anthocyanin, indicating that high light intensity is imperative for coloring in red Chinese sand pears. Bagging treatments did not affect contents of total soluble sugars, but decreased organic acids contents in fruit. In the second experiment, fruit of ‘Meirensu’ and ‘Yunhongli No. 1’ were covered with only one type of light-impermeable bag during the early development stage and totally re-exposed after the bag removal 15 days before harvest. Fruit were then collected at different intervals to trace the time-course of coloring, and related physiology and inner qualities. With increasing time after the bag removal, the concentration of chlorophyll, carotenoid, flavonoid and total phenols changed little, but the concentration of anthocyanin accumulated extremely fast within 10 days after the bag removal in both cultivars and thereafter kept constant. ‘Yunhongli No. 1’ had higher anthocyanin contents and lower hue angle than ‘Meirensu’, indicating a higher potential of anthocyanin synthesis. After the bag removal, the sucrose contents and PAL activities increased gradually and correlation analysis revealed that they were highly correlated with anthocyanin accumulation in two cultivars. This study suggests that anthocyanin biosynthesis in red Chinese sand pears is a highly light dependent process and modified by genotypes. Based on the current results, in order to obtain red Chinese sand pear fruit with attractive appearance and good inner qualities, fruit must be covered with light-impermeable bags at the early stage of fruit development and the bag should be removed totally at least 10 days before harvest.     

冬小麦叶茎粒可溶性糖含量变化及其与籽粒淀粉积累的关系

在池栽条件下研究了鲁麦22和鲁麦14两个冬小麦品种旗中、倒二茎、籽粒糖含量及籽粒淀粉积累速率的变化。结果表明，小麦叶片可溶性糖和蔗糖含量在开花后15－20d出现高峰；茎可溶性总糖、蔗糖和果聚糖含量变化呈单峰曲线，最高含量亦出现在花后15－20d，而籽粒可溶性总糖和蔗糖含量在灌浆期呈下降趋势，花后20d至成熟期各器官糖含量与籽粒淀粉积累密切相关。     

对蜂蜜中主要抗褐变因子的探讨

选用ＡＧ５０Ｗ－Ｘ８阳离子交换树脂，并以批处理的方式，成功地将蜂蜜中的肽类物质与其它组合得到了分离。抗褐变实验结果清楚地表明，蜂蜜中的肽类成分完全没有抑制褐变的活性。这与以前的报道截然不同。     

甘蔗蔗汁锤度和还原糖分傅立叶变换近红外定量分析数学模型

以傅立叶变换近红外光谱技术为基础，采用透射测定方式和PLS算法，建立蔗汁锤度和还原糖分定量分析数学模型．蔗汁锤度和还原糖分预测数学模型的决定系数(R^2)分别为0．9990和0．9953，均方根差分别为0．1150％和0．0722％，预测误差接近常规分析方法的误差．     

山东苹果中可溶性糖,有机酸的研究

本文报导了用高效液相色谱法连续两年测定山东主要栽培苹果总糖含量为８．９２％－１２．５６％。其中果糖含量为５．４４％，葡萄糖含量为２．８２％，蔗糖含量为１．９５％，决定品种差异的糖类为蔗糖，有机酸含量为０．７６％－０．９３％，其中苹果酸约占总酸８４％，其余为琥珀酸、草酸、酒石酸、乙酸、柠檬酸。研究了气候、土壤条件、肥料对糖酸的影响，并根据测定结果提出鉴定苹果品系可用果糖／蔗糖或葡萄糖／蔗糖，果实品质     

含糖类物料的喷雾干燥

从玻璃态转变温度着手,分析了在喷雾干燥中含有不同品种糖类物料粘壁的原因,提出了改性或在设计干燥流程时的6种应对方法。     

可发酵碳水化合物减少猪场臭气的机理和应用

可发酵碳水化合物,添加在猪日粮中到达后肠作为微生物发酵的底物,通过改变猪肠道和粪便中的微生物及其发酵过程,改变粪尿的理化特性,来减少氨的挥发以及臭气的产生。本文对臭气和除臭方法进行了简单的介绍,并综述了通过在猪日粮中添加可发酵碳水化合物来控制猪场臭气的机理和应用效果。     

Mineralization of “non‐metabolizable” glucose analogues in soil: potential chemosensory mimics of glucose

Glucose is widely used to study the dynamics of easily available organics in soil. Pure culture studies have revealed that many microorganisms can sense and respond to glucose through chemosensory mechanisms that are not directly reliant on energy catabolism. However, the rapid mineralization of glucose by microorganisms makes it difficult to disentangle its energy effects from such non‐catabolic interactions. “Non‐metabolizable” glucose analogues have proven useful in mechanistic studies of glucose in pure culture, but have never been applied to complex microbial communities in soil. We sought to determine how their mineralization in soil differs from that of glucose, and whether they have potential as a new approach for investigating chemosensory mechanisms in soil microbiology. We incubated soil from an agricultural Haplic Luvisol under controlled conditions for 24 d and monitored CO₂ efflux after addition of (1) glucose, and three “non‐metabolizable” glucose analogues: (2) 2‐deoxyglucose (DG), (3) α‐methylglucoside (αMG), and (4) 3‐O‐methyl‐glucose (OMG), at three concentration levels, along with a control. All three analogues did in fact produce a large increase in soil CO₂ efflux, but the dynamics of their mineralization differed from the rapid degradation seen for glucose. At medium and high concentrations, CO₂ efflux peaked between 2.5 and 4 d after amendment with DG and αMG, and was delayed by about one week for OMG. The markedly different patterns of mineralization between glucose and OMG offer a new tool for investigating the behavior of glucose in soil. By using OMG as a glucose model, chemosensory mechanisms could be studied with limited interference from energy catabolism.